Bizarre Outer Shell on a model? Only Appears in pose and object mode
Your issue lies in the topology. You have double vertices almost everywhere (multiple vertices at the same position in space). This would probably ruin the weight painting leaving parts of the mesh stretched as shown in your pictures. On top of that, back face culling is enabled so any back facing normals will not be shown. This meant that very small slithers of the mesh was being shown making it look like as you said, a ghost mesh.

To fix it you will probably have to remove double via W in edit mode, and then the remove doubles button. Probably a good idea to recalculate your normals with ctrl+n. Then you will likely have to redo the weight painting on the bones.